Violet Ray’s owner has placed her in some heavy duty (and expensive) slave training for a few years before she’s lent out to various stallions and mares across Canterlot for a sizable return.
 
Part of her training includes a permanent rubber suit, cutie mark removal, diaper training and of course a heavy dose of hypnosis to wash the mind clean.
 
Her hooves receive daily moisturizing and sensitivity training, resulting in the most heavenly hoofjobs for her future caretakers.
 
As part of the deal, the owner can choose to take a significantly reduced cost by allowing the slave to become a “breeder” for their duration of stay. Breeders are pumped full of stallion seed and put through an accelerated birthing process, before ultimately giving birth to a newborn foal that is immediately put up for adoption, at cost. Given Equestria’s mostly female population, adoption rate is extremely high, ensuring there is always demand.
 
While her body will shift towards a larger, looser self during over time, magical procedures ensure that she will be right back in tip top shape at the end of her training. But no need to do that before it’s necessary, right?
 
She’s only a few months into the training. Time will tell how much farther her mind — and her body — will be molded into its new role over the coming years~
 
(Non-pregnancy variant)